Sinks: The sinks started out very high (2-630 ppb) on Aug 29. This was because the Friday before Monday morning testing, hot water was flushed before turning off the sinks. So the first draw when turning on the cold tap on Monday morning was actually formerly hot water since cooled to room temperature while sitting in the sink gooseneck over the weekend. Thus these results accurately reflect the contamination of the hot water. Its not surprising the hot water has lead in it–the hot water pipes were not replaced. To avoid getting 630 ppb lead, always let the cold water run before using it!! On Sept 5th, the results looked a lot better but were still too high (2-44 ppb). The results were better because on this occasion, cold water was flushed on Friday before turning off the taps. These samples really reflected cold water. The results were still not clean because of cross-contamination from the hot water supply through sink aerators. Hot water flushing was conducted without removing aerators and regular hot water usage occurred with the aerators. Both lead to lead particles in the hot water pipes (dislodged bits of lead solder or gunk from the bottom of the hot water heater stirred up from a circulation pump replacement) collecting in the aerators. This then contaminates the cold water as it comes out of the faucet. The Sept 26 results were much better (0-10 ppb), with nurse sink <1 ppb, teacher’s sink <1 ppb, and the kitchen sink 4.5 ppb. This is because aerators were removed prior to testing.

Update: NPS says that “The aerators will be replaced on all sinks, with the exception of the nurse, staff, and kitchen sinks. We will leave the aerators off those sinks because consumption is possible and we know that the water is safe without them.” This should mitigate future cross-contamination at nurse, staff, and kitchen sinks. However, we should anticipate lead particles accumulating in classroom and bathroom sink aerators over time, leading to cross-contamination at these sinks in the future. (How quickly or severely we don’t know.) If this occurs, additional testing is not planned for these sinks, so we would not know.

Fountains & Bottle Fillers: On August 29, fountains and bottle fillers tested high (up to 20 ppb). On Sep 5 they tested lower but still high (up to 11 ppb). On Sep 26 the highest was down to 2.7 ppb (the fountain by room 10) and all others were <1 ppb. Its good that the numbers are going down but it remains puzzling. Where was the lead coming from on August 29 and September 5th? What changed to improve the numbers? Without clear answers, how can we be confident the mysterious lead won’t be back?

“Water main”: First, do not freak out. When the spreadsheet of results says “Water main” the do not mean the water main. They are referring to testing the water close to the water meter where the service line enters the building. What is the difference between “water main”, “water main (2″)”, “water main (4″)”, and “sample poured prior to water meter”? We are not sure, but we believe that these are all samples taken from inside the building, not in the street. One reason the result may have been high, but is now okay (although not perfect either), is that the water meter itself had lead in it, contaminating first draw of water that had been sitting in the meter. Now that the meter has been replaced that would not be a problem. The belief is that water coming into the school is clean. We are going to followup however, to find out what “water main (2″)” and “water main (4″)” refer to.

Copper: Copper was very high 130-8970 ppb on Aug 29. Is this normal? It probably is but no one ever tests for copper after installing new plumbing. Probably everyone drinks unsafe levels of copper for the first month in a new home. Copper is highest when newly installed. Overtime, as water runs through the pipes, the interior surface of the copper pipe oxidizes and becomes stable so that less copper leaches into the water. Copper levels were just as high on Sept 5 (194-9320 ppb). However, as of Sept 26, copper levels are down within the acceptable range (71-600 ppb). [The EPA action level is 1300 ppb.] We hope they continue to fall.